KANSAS CITY, Kan. (AP) Kevin Harvick had just taken the checkered flag for the fifth time this season, wheeled his car into victory lane and bathed in another confetti shower when he lamented what could have been.

Come again?

"Still wasn't really happy with it," Harvick said of his No. 4 for Stewart-Haas Racing, which he set a record in Saturday night at Kansas Speedway by becoming the fastest to five victories.

"I think," Harvick said, "we can make it better when we come back."

That shouldn't make the rest of the Monster Energy Cup Series feel very good about things. Harvick has won back-to-back races after a three-race win streak earlier this season, and heads into next week's All-Star race at Charlotte as the one guy head and shoulders above everyone else.

But his response to his victory at Kansas, where he overcame trouble getting through inspections and a car that was off much of the night, speaks to a couple of very crucial facts.

First, it shows how demanding Harvick is of his team, and how nobody in the garage is willing to settle for greatness - not when there is perfection to chase. Pit stops could be cleaner, the car could handle the least little bit better, and the margin of victory could be even more comfortable.

"They're hitting on all cylinders," marveled reigning series champion Martin Truex Jr., who was in a similar spot last season, when he reached victory lane eight times. "They've got a great balanced race car and they're doing all the right things, and we're just a step behind that."

So is everybody else.

The second thing Harvick's response to his victory demonstrates is that, well, he hasn't changed a whole lot over the years. Harvick earned the nickname "Happy Harvick" as a joke, a play off the fact he was prone to emotional outbursts.

And while he may have mellowed over the years, that streak is still in there, capable of rearing its head at the most unsuspecting of moments.

Given the way the season has gone, though, Happy Harvick probably ought to be simply happy.

He began his winning streak at Atlanta, continued it at Las Vegas and made it three straight with a triumph in Phoenix. An early wreck in California ended the streak, but he finished in the top 10 in each of the next five races, including a second-place run at Texas and a pole at Talladega.

Harvick returned to his winning ways at Dover, when he started second and led 201 of the 400 laps en route to a dominant victory. And the hot streak continued at Kansas, where he had to race out of the garage for qualifying because of problems at inspection and still landed on the pole.

He was clearly the fastest car on the track early on, then struggled to keep pace with Kyle Larson and Ryan Blaney through the middle stretches. But a series of late wrecks, including a tangle between Larson and Blaney that knocked the latter from the race, reset the field for a final sprint.

With four fresh tires, Harvick roared from sixth on the restart with 10 laps to go, chased down Truex at the start-finish line of the final lap and cruised to his record-setting win.

One that left everybody else feeling just a bit helpless.

"There isn't a real bright shiny tool you can use and say, `There it is!'" said Joey Logano, who finished third. "It's just a bunch of little things. They're doing everything right. They've got a ton of speed, they're qualifying first and they're winning a bunch of races."

Indeed, the entire Stewart-Haas stable has had a ton of speed this season. Clint Bowyer ended his long victory drought at Martinsville, and teammate Aric Almirola was in the top 10 on Saturday night.

"I think as an organization all our cars are running better, which is exciting to me and everybody back at the shop," said Greg Zipadelli, the team's vice president of competition. "It's crazy to see what these guys have done this year. It's just really cool. You have to keep riding it."

Harvick said the same thing: When you're on a hot streak, you have to ride it as long as possible.

Maybe that's why he bemoaned what little bit of speed was left on the track Saturday night, and why he is pushing his team so hard despite so much success. He knows that everything can spin the other way in a hurry, and that it's time for him to make the most of his chance out front.

"This is something you may never do again in your career," crew chief Rodney Childers said, "where you have fast cars and guys who give you everything they can, and a driver who gives you everything he can. You have to fight each week. If it's eight races you win, if it's 10 races or 12 races you win, that is what your goal should be, no matter what race team you are. You got to keep going."